Hearing aid



FIG. 1 is a perspective view of a hearing aid;

FIG. 2 is a front view of a hearing aid;

FIG. 3 is a rear view of a hearing aid;

FIG. 4 is a left-side view of a hearing aid;

FIG. 5 is a right-side view of a hearing aid;

FIG. 6 is a top plan view of a hearing aid;

FIG. 7 is a bottom plan view of a hearing aid; and,

FIG. 8 is a perspective view of a hearing aid showing the hearing aid in a state of use.

The broken lines in FIG. 8 are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design. 

CLAIM The ornamental design for a hearing aid, as shown and described. 